Process of making plastic film articles



. Oct. 31, 1939. a T. FERNGREN ,178,393

rnocnss OF MAKING PLASTIC FILM ARTICLES Filed Jan. 12, 1932 s Sheets-Sheet 1 INVENTOR Oct. 31, 1939 E. T. FERNGREN I 7 PROCESS OF" MAKING PLASTIC FILM ARTICLES 7 Filed Jan. 12, 1932 3 Sheets-Sheet 2 INVENTOR Oct. 31', 1939. "E. T. FERNGREN 2,173,393

PROCESS OF MAKING PLASTIC FILM ARTICLES I Filed Jan. 12, '1932 3 Sheets-Sheet 3 FIIGL. 13

Patented a. 31, 1939 PROCESS OF 2,178.39: MAKING ms'rro mu ARTICLES Enoch Ferngren, Toledo, Ohio, assignor, by

mesne assignments,

to Plax Corporation,

Hartford, Conn., a corporation of Delaware Application January 12, 1932, Serial No. 586,184

20 Claims.

invention relates to a process of molding plastic materials into articles of hollow form,

such as cups, milk bottle caps, bags, cartons etc.

into a suitable solid state and the recoveryoi' solvents therefrom.

The invention further relates to new methods of removing hollow molded articles from molding implements.

Theinvention' also includes a novel procedure.

of gum-coatingthe edges of molded hollow articles, such as milk bottle caps, a novel procedure of printing the same and of nesting the With relation to specific articles, a number of difierent typesof sanitary milk bottle caps are shown in the accompanying drawings, some of which are entirely new in their relation with a bottle mouth andotherwise meritorious for their intended uses.

The invention also concerns the incorporation of bacteria-destroying ingredients into the plastic material used, so as to afford the dairy industry and the publicadditional safeguards.

' The various caps shown, which may be made according to this or related processes, are to be molded or formed from various plastic materials 30 in a fluent or dispersed state with solvents and plasterlzers, or from any transparent material which can be maintained in a fluent state, either by heat or by solvents. Cellulose acetate or nitro cellulose, properly plasticized and in solution 35 in one or more suitable solvents. are the preferred types of the cellulosic plastics that may be molded according to this process, but many other types of transparent or translucent plastics are now also available on a commercial b'asis, such as amino plastics, paramn plastics,

sugar plastics and ,othersynthetically produced compounds and resins, which may be molded according to this-process.

In the forming of film wall containers from materials in solution in a solvent or otherwise, it is an object of the present invention to deliver a specific quantity. of the fluid material by a force feeding-action as a single charge into a mold unit, the quantity being predetermined, with relation to the surface area of the mold which is to be covered thereby, the proportion of ,solids to solvents present, the viscosity of the solution and the thicknessor weight of film required.

It thefllm wall is formed from a plastic mate- 55 rial which is maintained in a fluid state by heat,

articles in progressive order, as they are made.

the predetermined quantity to be charged into the mold will depend on the spreading capacity of the fluid as influenced by the temperature of the interior of the mold at the speed of rota tion employed, with reference, to the surface which is to be covered and the thickness of film deposit required. The object in this instance resides in coordinating the speed of rotation of the mold and its temperature according'to the known requirements of the plastic material used. Another object is to spread the plastic material in a substantially spiral path over the interior surfaces of a mold by a rotational action of the mold, which is caused to be slow or fast, intermittent' or continuous, and during which time 15 the mold may be held at difierent angles or oscillated or vibrated to suit the requirements. for distribution of the plastic material placed therein, with relation to the amount of strength and thickness, it is desirable to impart to any 20 one portion of a film article. In this connection, for instance, in the making of bags it is always desirable that additional strength be provided at the point where the bottom portion joins the sides accordingly the rotations or the angles at which the bag mold is held should be directed toward increasing the thickness at such point. Again, if a carton or bag be square. in shape, intermittent movements both as to rotation and oscillationmay be necessary to provide the desired strength at the corners. In the case of a cigar slipover cover or a milk bottle cap, where the greater strength must be placed in the region of the, closed end, a continuous rotation with the mold oscillated between an upright I and a partly inverted position will suflice.

Still another object of the invention resides in the method of treatment of the material for the speedy removal of solvents therefrom and to increase the density of the film.

In connection with the milk bottle caps shown herein, some of which have sunken center portion's arranged to fit into an ordinary seating re-v cess in the bottle mouth, the object is to shape the upper film wall to flt into the cavity above the seat edge so that the film will lie closely above 7 the regular paper cap and thereby to avoid any possible fracture of the film wall by sharp particles of ice or other intrusive objects, and thus insure the certainty of a protective covering against contamination. However, in the case of more rigid caps, moldable by this process, when different sealing features are involved, or when reinforcing sealing disks are incorporated as a part of the sunken portion of the cap, the

provision of .a sealing feature at the seat edge is an object oi the invention.

It may be noted that the sunken median disklike section of the cap has rounded corners, or curved side walls, the object of this shaping being to avoid too close a flt with the inner side of the lip wall of a bottle, so that the air in this cavity may have clearance to escape during the entering oi the plug-like section of the cap at the time of capping.

All the caps shown may be molded with sunken or depending portion; of course, they may also be manufactured without this feature, as required.

The sealing of the cap with the bottle mouth is eflected largely at the top and outer side of the lip bead at the mouth of a milk bottle; but if the shape of the bottle mouth requires the sealing to be more eflected at other points, such requirements may be accommodated by an appropriate change in the form of the cap.

As heretofore pointed out many diflerent plastic materials may be used in the moldin of tissue-like articles by this process, however, articles having much heavier walls, such as cartons, bottles, cans and boxes, may also be produced. Such articles may require much larger molds and diflerent assemblies, but such changes will in no way impair or hinder the practice of the process and will come within the scope of this invention.

The invention will be understood from a consideration of the accompanying drawings which show by way of example several embodiments thereof. In the drawings:

Figure 1 is a vertical sectional view of a mold assembly for producing milk bottle caps, showing. the position of the charge feeding nozzle, before delivery oi plastic material;

Fig. 2 is a similar view of the mold with the feed nozzle in the position it occupies after it has delivered a charge of material into the mold and prior to its upward recession from the mold;

Fig. 3 is an assembly view substantially in central vertical section showing the drying cup and its associated parts as they are positioned during the early period of the rotation of the mold and the extraction of solvents from the plastic material;

Fig. 4 lsa view similar to Fig. 3 showing the relative position of the parts during the removal of the film bottle cap from the mold;

Fig. 5 is an assembly view substantially in vertical section showing the drying cup and the edge-holding ring in relation to the edge cutting means and the suctional pick-up head at the instant of severanceof the bottle cap from the edge ring;

Fig. 6 is a view principally in elevation and partly in vertical section showing a suction head or pick-up as it is positioned after it has transported a bottle, cap and nested the same;

Fig. '7 is a view principally in vertical section showing a recessed type of bottle-cap-moving suction head which is suited to take the cap directly from the mold, the rotary edge trimming means shown cooperating to cut away the lower marginal edge of the bottle cap from the outer edge of the mold;

Fig. 8 is a view principally in elevation, but with parts broken away and in vertical section,

showing how a bottle cap may be printed or em-- bossed while supported on the kind of a head shown in section in .Fig. 7;

a,17s,sos

Fig. 9 is a view partly in vertical section and partly in elevation showing the bottle cap sustained by suction from a pick-up head while the lower edge of the cap is being immersed in a solution of rubber or some other gummy adhesive contained in a suitable receptacle;

Fig. 10 is a view partly in elevation and partly in vertical section of the upper end of a milk bottle with a molded cap positioned thereon, showing a rubber seating plug used for forcing the cap into place and holding it closely to the upper edge of the bead of the bottle while crimping rollers operate to stretch the film and conform it closely to the bead of the bottle;

Fig. 11 is a view partly in elevation and partly in vertical section illustrating the manner in which an adhesive or a colored coating may be applied to the outer side of the skirted portion of a milk bottle cap; a suction head member holding the cap while rotating it against the outer edge of a pick-up or transfer wheel, which isalso rotated and which has its lower edge in contact with the material that is to be transferred to the cap;

Fig. 12 is a view principally in vertical section, but with some parts in elevation, showing a heated crimping roller operating on a skirted portion of a milk bottle cap to stretch or fold the same under the beaded portion of the milk bottle;

Figs. 13 and 14 are views inperspective, the latter having parts broken away and in section, illustrating bottle caps with a sunken or recessed center portion which is shown in Fig. 14 as being reinforced by the ordinary disk cap;

Figs. 15 and 16 are views similar to Figs. 13 and 14 respectively showing a type of milk bottle cap suited to be stretched across the top of a. bottle, the section in Fig. 16 illustrating a reinforcing sealing pad formed as a part of the upper end thereof;

Fig. 17 is a view similar to Figs. 14 and 16 showing a molded cap with a crimped skirt;

Figs. 18 and 19 are views respectively in perspective and elevation showing a preferred type of cap where the skirted portion is divided into upwardly curved and flared portions which when reversed assume the shape shown in Fig-19, ritting snugly around and under the head of a bottle neck; and

Figs. 20 and 21 are elevational views illustrating a form of cap which may be molded of any material, but preferably should be somewhat elastic in nature; the dotted line on the cap (Fig. 21) indicates a weakened line along which the cap may be split or torn when removing it from the bottle neck, this cap being also moldable with a diagonal split in its side wall and without any weakened or scored section.

In carrying out the process of molding a product such as coverall caps for milk bottles,

the essential steps for certain types of caps are anaaos plastic material in a fluent state, is extruded and 4, duringtfie rotation thereof.

zle once the extruding impulse is terminated.

The charge 1 being received, the mold 2 is rotated, while an edge holding ring 9 and a drying cup housing ill are'immediately assembled thereon to form an airtight chamber, as shown in Fig. 3.

Both the ring 9 and the cup-shaped housing It are pressed against the outer conical surface H of the mold 2, which acts as a clutch, causing the cup and the .ringto rotate in unison The mold 2 is caused to revolve around its axis at any suitable speed by means of a tubular member [5 which isdriven by suitable mechanism (not shown). mounted in holding means, which are caused to impart any required tilting movement to the mold 2. The cup l and its associated parts are likewise caused to participate in the tilting and rotating movement of the mold. This rotating movement will cause the charge I of plastic material to be spread in a spiral fashion within the mold cavity 5. None of these mechanical parts are shown herein, but may be of any conventional or desired nature.

The drying cup III has a hollow stem i6 through which extends centrally a pipe i'l. On the outer end of the-pipe I1 is mounted an air deflecting member l8, which as shown in Figs. 3 and 4, is open at its wider end. This member may also be closed at its wider end as shown at iii in Fig. 5, and will then function as a temperature controlling chamber to absorb or radiate heat as may be desired, in which case passages 20 and 2| provide means for circulating suitable fluid media therethrough.

As the mold charge 1 is being spread over the inner face of the mold 2 by the rotation of the mold, and so distributed that a thicker film layer will be provided over the valve head 4 and in an annular' groove 24 of the mold, air or other gaseous medium is admitted through an annular passage 25 in the stem l6, which air is then. forced or drawn out by vacuum applie through the passage 26 in the pipe I'I'.

The layer, of the charge I, in the mold cavity 5 is caused to advance toward the edge iii of the ring 9, but not beyond this edge, by bringing the-mold 2 into the position shown in Figs. 3 The air admitted through the drying cup l0 should be free from moisture to prevent any condensation 'of water during evaporation of solvents or during compression of the air.

After the spreading of the film in a manner such as to secure the required distribution thereof, it is exposed to a pressure and vacuum treatment, which may be modified, varied orapplied .intermittently to the film, Many solvents, if

The member i5 is slidably of the film. To avoid such partial drying and to take full advantage of the vapor pressure .of

.solvents in the film it .is preferable to reduce the atmospheric pressure in the mold cavity-directly outside of the film coating, while at'the same time either maintaining a reduced circulation of air, or intermittently circulating air, followed by rapid increases of pressure of momentary duration in that atmosphere which is in contact with the film. f w

, Increased pressure" intermittently applied against the film has a tendency of wringing out or separating the solvents from'the solid material of the film, bringinga greater amount thereof near the surface of the film. If the pressure is reduced below that of the atmosphere at this point of the operation, a considerable part of the solvents will evaporate. If this alternating pressure treatment is continued, the film is quickly freedof solvents and the solid portion thereof compressed and increased in strength, flexibility and density.

The treatment of a fluent plastic film by means of a compressible fiuid also tends toward the prevention of any creeping tendency in the fluent film. In the forcing out of solvents from the solid material, relatively dry air, which has been cooled and suitably compressed, is admitted through the passage 25 or 26, as the case may be, and brought into contact with the plastic coating which-has been spread on the walls of the mold.. This pressure action, which may be progressive in its nature, from a low to a' "high pressure, has the tendencyto hold the coating rigidly in contact with the wall of the mold. When the negative pressure condition is brought about, the tendency is to increase the rate of release of the solvents. The action of the pressure when it is reduced to some negative value should be accompanied by a slow circulation past the film in the mold, either toward the passage 26 or toward the outer rim IQ of deflector l8, and-thence through the passage 25 to a suitable solvent recovery apparatus (not shown).

During the foregoing procedure, it will be advantageous to control the temperature of the molds and the air conducting means used. In this connection, it should be noted that the air stream used and circulated pastthe fluent film should be properly controlled as to temperature.

The efiect on the solvents of the variations of the pressure and sometimes of the temperature is to cause an increased or intensified rate of removal of solvents as a relatively thick vapor from the viscid plastic material, which speedily looses its fluency. Repetition of this differential pressure treatment, with or withouta very rapid movement of air over the film, will result in a, stable film practically free from solvents, and

from which remaining traces of odors may be removed by a subsequent flow of air through the space between the deflector I8 and the exposed surface of the film. In this connection it should benoted that the deflector i8 is shaped to promote a uniform sweep of air at all points of the mold cavity, independently of the direction of the air current. v

If a subsequent heat treatment of the film should be desirable for any reason, the molds and the air used may be heated. If a material acted on too directly or intensely by a strong cirsuch as rubber or a rubber compoimd is to be molded by this process, the air may be heated to eiiect a curing or vulcanization oi the layer of rubber in the mold, while the diiferential pressure treatment is valuable to increase the density and remove pin holes and other defects.-

11 a plastic material is of a nature to be solidi fled by heat and pressure applied simultaneously thereto, this process affords every facility for such treatment, as the molds may be heated in any well known way and the fluid temperature controlling media may be of a liquid nature, it so required for certain treatments where high heat conductivity is essential, in which case the pressure would be hydraulic instead or pneumatic.

In the event that a plastic material is employed which will require chemical action for its coagulation instead of heat and pressure, or the vacuum treatment as above set forth, modifications in construction may be resorted to, such as minute perforation of the valve head 4 by which the film may be given the necessary treatment from its rear side during the coagulation period.

Again, it a molten plastic is used from which no dispersing agent or volatile material needs to be extracted, nor any chemical reactions established, the compressed air employed should preferably be heated to the same temperature as the molten plastic material, when it is first admitted to the mold cavity 5 during or-following the first spreading of the hot charge. Increased temperatures of the air and the mold used, with proper regard to the peculiarities of the plastic material employed, will aid in developing the right amount of mobility in the charge, during the spreading period asthe mold is rotated with the air admitted through the center of the cup from passage 28, but thereafter the air may be swiftly cooled in order rapidly to solidify the fluent material.

When the film on the mold 2 becomes solid, its removal from the mold may be accomplished partly by mechanical action and partly by pneumatic actuation, or the employment of a suitable vacuum action through the passage 25, to establish a low pressure atmosphere on one side of the film while a slightly compressed atmosphere is introduced through a passage 33 in contact with the rear side of the fllm.

, The valve head 4, which forms the central bottom portion of the mold cavity 5, has a stem 21 provided with a spring retaining head 28 at its lower end. This stem and the head 28 are movable as a unit in the passage or bore 33 of the member I5. A compression spring 29 is located between the retaining head 28 and a perforated partition 30 of the mold, by which expedients the head 4 is kept in close contact with the cylindrical seat edge 23.

The operation of releasing a film cap 35 from the mold comprises slightly raising the valve head 4 from the seat edge 23 by the action of compressed air supplied through the passage 33 in the member I5 and thence through small passages 32 and SI, while coincident therewith vacuum is applied through the passages 25 and 26, or through one of these passages, while the other one is closed oil. This results in the lifting or I separation by differential pneumatic pressure of the skirted portion IOI of the film cap from the annular groove 24 to the upper edge I4 around the side wall of the mold. As this takes place, the cup I andthe attached edge I3 of the ring are moved slightly outwar y, away from contact with the surface II of th mold, placing the film wall at the edge I4 under an outwardly stretching strain, as the air from beneath the valve head moves along the side of the mold toward the edge I 4. with the result of freeing the film from the edge I4. At this instant the movement of air from the tubular member I is nearly discontinued as the spring 29 is no longer compressed with sumcient force to maintain an open space between the lower face of valve 4 and the seat edge 22, with the result that the valve head 4 immediately snaps into its closed position, while the air between the skirted portion of the cap and the mold will strip the sunken portion I02 of the cap from the surface 3 oi the valve head 4. The application of vacuum through the passages 25 or 28 is discontinued as the valve 4 resumes its normal position; and air under a slight pressure should then be injected from the passage 25 and around the deflector I3 toward the curved portion I03 of the cap and thence outwardly through the passage 26, so .as to maintain the cap 35 in proper shape, as shown in Fig. 4.

The cup I0 and the ring 9 are now brought into the position shown in Fig. 5, where a pick-up or transfer head 38 is brought into contact with the sunken portion I02 of the cap, and a cylindrical cutter 40 is brought into close proximity with the edge l3 of the ring 0. During this time the film cap is still attached to the edge l3.

The transfer head 36 is carried by a tube 31 having a passage 43 therethrough which is connected by other conduits and valve arrangements (not shown) to any suitable air exhausting and air compressing devices. The arrangement is such that when the head 36 is brought into alignment with the ring 9 and the cup I0, air is partly exhausted from the hollow interior of the head through the passage 43, which draws air through bores or passages 33 in the head and attracts and holds the portion I02 of bottle cap thereto.

Air under slight pressure is now preferably admitted through the passages 25 and 25 to distend the cap 35 outwardly, while a part 39 which carries the cutter 40 is either given a downward or the cup I0 an upward movement, thereby causing the cutting edge 4! to loosen, strip or cut away the outer edge of the flared film portion I04 of the cap 35 from the holding edge I3 of the ring 9.

The completed cap is now carried by the head 36, first upwardly and outwardly through the cutter 40, and thereafter to a stacking device or paper tube 34, where the caps are nested; and a certain packing impulse is given as the cap is delivered from the head 36 by the release of compressed air from the series of passages 38, this air passing radially outwardly between the curve 42 of the head and the curved portion I03 of the cap.

In a case where plastic materials are used for molding hollow objects by this process, which do not require any edge holding parts such as the edge I3 of the ring 9, or if pressure treatment may be unnecessary, a rotary edge trimmer 5|, such as that shown in Fig. 7, is associated with the edge I4 of the mold, the several shearing knives 52 being arranged at an angle relative to the edge I4, so as to out or slit the film layer in a radial-tangential fashion with the cut moving from the inner side of the film outwardly along edge I4.

After this trimming action, a transfer head 45, which has a threaded connection indicated at 48 I 9,178,898 with a hollow pipe 44 and which is provided with a rubber cushion 41 having a raised corner brim 50 and passages 48 and 48, is elevated or other! wise concentrically inserted into the'm'old 2 to align the brim 50 with the curvedportion I08 of the cap and to bring-said brim close to the cap. At this time the air between the upper face of the head 45 and the film layeroverthe valve head 4 is evacuatedby withdrawing air from the pipe 44 and the passages 48 and 49; while simultaneously compressed air is discharged between the seat edge 23 and the valve 4 advanced into the evacuated cavity inside the brim 50 at the top of the transfer head 45. v I

The compressed air issuing from beneath the valve 4 quickly releases the skirted portion IOI of the cap from contact with the wall of the mold.

' When the compressed air application is 'terminat- I .ed, the valve head 4 separates the portion" I02 of the cap from contact with the surface 3 of the valve head 4, this last stripping action being aided by the'suction action from passages 48 and 48.

The main body of the mold 2 may be slowly moved rotationally an inch or two at its periphery as the valve head 4 is seated in the recess inside the brim 50 of the cushion 41, which will exert a tortional stripping pull on the skirted portion of the cap as the air is moving outwardly between this portion and the inner wall of the mold from beneath the valve head 4 to the edge I4.

The transfer member 45, to which the cap 35 is held by suction, is now moved downwardly and outwardly from the environs of the trimmer 5I. The finished, cap may now be stacked and nested in afashion similar to that described with relation to Fig. 6, but the position of the cap is now reversed, that is, the small end thereof is now foremost when it enters the tube-or is nested.

When it is required, the caps may be embossed or printed in one or several colors as they are carried outwardly by a transfer headsuch as the head 45, Fig. 8. The head moves the caps along a predetermined path during which a part 59, which serves as a carrier and guide for a reciprocating piston 58 is caused to come into alignment with the recessed .or sunken portion I02 of the cap while moving in the same direction as the head 45.

Each piston 58 carries die parts 55 and 51, of which the part 55 may be an impression member. This member should preferably be formed of a fairly elastic or non-rigid compound when applying impressions to fragile or soft films. However, any suitable type of material may be used for this die member. When embossed or raised eflects are wanted, the upper surface of the head 45 may be provided with an insert die of firmer or more rigid material. I

The upper die member 55 may be heated to facilitate the draw in certain film materials and when coactive upper and lower impression members are used for obtaining diflerent effects. The upper surface of the head 45 may also be a means for transferring a color pigment to the inner face of the film portion I02. In order to'obtain two or three color effects the easiest procedure is toempl'oy successive printing devices of the type shown in Fig. 8, which devices may be timed and synchronized by means to move at the same speed asthe head 45 at the time of effecting a printing impression by the movement downward of the piston 58 or an upward movement of the head 45. In order to provide a milk bottle cap suitable for all needs and uses and readily to seal it with the beaded portion of the neck of a milk bottle,

a gum coating 58 may be applied to the flared is carried by the transfer head 45, the angle of immersion or of association with a bath of gum or a gum-applying means may be difl'erent. In the event of applying a colored coating to the entire skirted portion of a cap, the angle may be suchas to contact the entire outer side of the skirted portion with a coating 54, Fig. 9, while rotating the head 45.

when employing a transfer head .35, as shown in-Fig. 9, a receptacle 55may be used to contain a gum solution or appropriate gummy substance. when the head 38 starts to submergethe lower end of the cap 35 in the'solution 54, the air inside the cap will prevent excessive coating on the inner side, the curved portion 42 of the head serving to support the curved portion I03 of the cap and the enclosed air serving further to imflared portion I04 of the skirted wall IOI of a cap.

In this figure a suction member 58 is shaped to hold the skirted portion IOI of a cap, this member being carried by a rotatable hollow'tube 51 and being caused to approach the periphery of a transfer wheel 82 which is rotated so as constantly to pick up a coating of. material from a bath 55 thereof in abasin 5I The wheel 52 is rotated by means of a shaft 53, between which and 40 the wheel is provided an annular recess 54 into which surplus material may drain from the side face of the wheel 52 and thence be deflected back into the bath 55 by any suitable means (not shown).

, 45 The coating 53 or gum deposit laid on the portion I04 of the cap may be varied as to thickness by the relative speeds of rotation of the member 58 and the wheel 52, so that great economy can be practiced in the amount of material trans- 50 ferred from the periphery of the wheel to the brim of any type of cap. I I

During the association of the member 58 with the inner side of a cap 35, suction ports 59 function to hold the cap securely as shown in Fig. 11, the amount of air exhausted through a passage 50 for effecting this purpose being relatively slight. When the cap is released from the member 58 by a'reversal of the direction of the air flow through the pipe 51, the air passes from the hollow interior of member 58 through the ports 59 to the space me between the flat portion I05 cap outwardly.

of the cap and the member 58 and moves the 5 If the cap is to be used directly after leaving 6 press the sunken portion iii! of the cap into the recessed portion 11 at the mouth of the bottle.

A paper cap 18, Fig. 10, may be a substantially integral part of the cap portion I82 if provisions are made therefore during the molding of the cap prior to the spreading of the plastic material in the mold. such as a recess in 'the valve head 4 for receiving the paper disk and appropriate mechanisms for transferring and placing the paper disks 18 in such recess. However, the paper disk 18 may be attached to the cap portion I 92 by any desired means after the cap has been molded or may be a separate object inserted in the bottle recess ll, before the molded cap is located therein or thereover. Both the paper disk and the outside cap may be forced into place in the recess II at the same instant to eliminate duplication of eifort or two operations of capping.

The useful features of the plug 18 reside first in that the depending central portion II" will locate the center portion III! of the cap in the recess 11, while the suction effective through the passages ll will pull the upper curved wall por-- tion I99 of the cap slightly upwardly and away from the top end of the beaded section 19 of the bottle, allowing the escape of air from the recess 11, and secondly in that when the plug 10 is fully pressed down, the outer elastic wall portion 18 thereof is eifective flexibly to grip and to urge the curved portion I83 of the cap downwardly where it Joins the skirted portion thereof. This gives the cap a snug or tight fit over the beaded mouth of the bottle and holds the film comprising the outer cap portions without inflicting injury thereto during the subsequent rolling operation of twisting rollers 8| on the skirted portion llll and the flared edge I84 of the cap.

Each roller 8|, of which at least three should operate at the same time, is made of rubber, and as shown in Fig. 10, has been advanced to bear against theside wall l8! of the cap. Each roller is rotated by means of a flexible cable 83, and is advanced toward or 'away from the bottle neck by means of an arm 82, while simultaneously a rotational movement is given to the capping device and the bottle as a unit, either in the same, or in the opposite direction of rotation as or from the roller 8!. The result of the combined stretching, twisting and folding action is about as shown at 88 in Fig. 10.

In Fig. 12 is shown an internally heated roller 98, for twisting and drawing the skirted portion of a cap around the bead 19 at the bottle neck. In order that the heat of the hollow roller 98 may have a softening effect on the film material of the wall i0! of the cap before the roller comes into' actual contact therewith, from five to seven of these rollers should be provided and spaced equal distances apart from each other. These rollers should also be equally spaced from the neck portion of the bottle, so that a zone of sufficient heat radiation will be available to give pliancy to the materials which enter into the composition of or comprise the heat sensitive component of the wall portion "ii of the cap.

The hollow roller. 98 is made of any suitable material, and may be provided with suitable diagonal grooves around its periphery. The roller is rotatable in a hub 84 of an arm 85 by means of a short tubular shaft 91, which is connected at its lower end to a nipple 98 secured to a hollow flexible tube 99 by means of a flange I99, welded to the shaft and to the nipple.

The nipple 98 has an upwardly extending tubular portion 95, which is spaced from the inner arrasea sides '0: the tube 01 and extends into a'hollow' space 95 within the roller 98.

The arm 88 is provided with projecting portions pivotally mounted in ring members 01 and has a split rearward extension 88 to which one end of an actuating arm 89 is pivoted by means of a pin 88. An inlet tube 90 passes through one of the ring members 81, this tube acting as a pivot pin for the upper end of the arm 88. The interior passage SI of the tube 99 is connected with a horizontal passage 82 of the arm 85.

The tubular shaft 91 has several perforations 99, which communicate with an outer angular portion of the passage 92 in the hub 84, so that constant communication is provided between the interior of the shaft 91 and the passages 9| and 92. Steam or other heat conducting media may be caused to advance through the connected passages into the cavity 94 of the roller 98 and thence outwardly through the tube 95 and the flexible tubing 99, the roller 98 being sufficiently heated as to be capable of reshaping the skirted portion H of the cap so that it will take on and permanently hold the same shape as the bottle bead or neck surface along which it is drawn, wrapped, stretched and/or folded by the action of the rollers, mechanically and/or by heat.

Each roller 98 is rotated by the flexible tubing 99 and is brought forwardly into contact with the cap and the bottle neck by a tangential thrust of the arm 89 alongside the ring 81. The bottle I09 may be held stationary if the ring 81 which carries the several rollers at equal distances around the bottle neck is rotated or the bottle may be slowly rotated by the action of the several rollers 98, such rotation of the bottle being partly resisted with a breakshoe action on the outside of the bottle or on its holding parts. The rotation of the bottle and the capping device as a unit may, if desired, be independent of the rollers.

The several bottle caps shown can all be molded according to the process herein disclosed, although other processes may also be employed in their final shaping and handling. Figs. 13 to 16 show caps which must be reshaped in their skirted portions to fit the necks of different types of bottles or containers, while Figs. 17 and 21 represent caps not entirely within this class. The caps shown in Figs. l8, l9 and 20, on the other hand, need no reshaping to fit over the beaded lip of an ordinary milk bottle.

The cap shown in Fig. 18 represents the most pronounced outward flare at the edge, and has the advantage, when stacked or nested, of being more easily picked up and separated from the stack by mechanical means than any other type. The skirted portion liii of this cap which is divided into a series of cupped sections or flounces H9, will, when reversed or turned downwardly, fit around the beaded portion I9 of a bottle with a fair degree of inherent grip, as shown in Fig. I9. Many varieties of caps can be made with an elastic or a partly adhesive film; also, latex compounds may be used which can be vulcanized in the mold, providing satisfactory, easily attached and well fitting caps, printed or otherwise, and in many colors.

The mold used in forming the cupped sections I I8 may be of the open type with a side wall brim formed to shape each section. The edge cutting member used for this cap when trimming the edges from the ring 9 associated with the mold is shaped to cut out the intervening film portions along the outline shown in Fig. 18. The

in Fig. 18, may be molded in the shape and posi-' tion of the cap shown in Fig. 19 and cut apart after molding as shown when they are trimmed from the edge holding element. These cupped sections llli may be so arranged or molded with relation 'to one another and to the bottle neck bead, that the adjacent edges .III will overlap as indicated by dotted lines in Fig. 19.

The outwardly flared ends I04 of the cap, shown in Fig. 18, may if required be coated or tipped on their extreme points, which will form their inner side when turned downwardly, with any suitable adhesive, as illustrated inFigs. 9 or 11, or may be coated en-masse, when stacked or nested.

The cap shown in Fig. 17 molded with a crimped edge I I3, the object being to provide a cap which will normally hug the incurving side of the bead 19 of the bottle. When this cap is slipped over the upper end of a bottle, the crimped folds below the point N2 of the skirt thereof may be readily flattened out by any smoothing or clamping device.

The cap, shown in Fig. 20, is adapted to fit closely over the widest portion of the bead 19 of a bottle and to come down to and closely fit a reduced diameter portion of the head at the point 4 of the cap. A cap of this shape can readily be put on by fitting one side of the wall I it well down over to one side of the bead l9, and then executing a rocking chair movement with the cap from the low point forwardly, while pressing downwardly on the head 19. The cap will then slip down over the widest portion of the bead. 'Aside from the assistance given by the outline of bead of the bottle the enclosed air presumably assists in distending the cap material as it passes over the widest point of the bead.

The cap shown in Fig. 21 is molded to fit further down on the bead of a bottle and is more diflicult to put on unless it is provided with a scored side wall section, which will permit the distension of the side wall 6 adjacent to the scored portion H5, which will open up under the downward pressure when the cap is forced over the bead 19 of the bottle to the position shown in Fig. 21. This scored portion or section N5 of the side wall of the cap may also be cut as shown. When removing a cap of this nature from a bottle neck, the section 5 and the remaining score line provides an easy way of lifting the cap from the bottle. The inner side of the section H5, may be gum-coated at its edge,

.or the cap' may be made of a compo ition which will normally adhere to the glass when pressed thereagainst.

The various bottle caps, described above, may be interchanged and so related as to serve other uses and needs in bottle covers. For instance, the 7 cap shown in Fig. 20 may be provided with an outwardly flared lower edge such as is provided on the cap 35, Fig. 13, in order to facilitate its nesting, handling and use, as stated in the introduction of the specification relating to the object of this'particular feature of the invention. Again,-

a universal cover all transparent cap shown in Figs. 11 and 15 may be given an opaque coating along its curved portion I03 and side wall or skirted portion "II in any color or metallic luster, leaving its center portion I05 clear and trans- 7 parent, so that merchandise or food may be inspected therethrough.- Such a cap it made in different dimensions will find use as a cover for a large number of bottles and wide mouth jars.

The process of this invention: is capable of variations in its steps for instance, if a deep mold is used it will aid operations if the mold be suddenly charged with a larger quantity of the plaster material than is required,'while spinning the mold more or less for an instant, and then immediately withdrawing a known surplus quantity of the plastic material from the mold 2 into the charging nozzle I. The ring 9 used for lifting out the film container may have a much wider surface at its edge I 3. Further, the ring 9 may be detachably carried by the mold 2, instead of by the cup l0.

Various changes within the scope of the appended claims may be made in the process of the ,invention as well as in the construction, form and arrangement of parts of the apparatus used, for practicing the same without departing from the spirit ofthe invention or sacrificing any advantage thereof.

Having thus described my invention, I claim:

1. The method of removing the solvent component from a plastic compound which is spread as a film coating on a rigid surface, which comprises causing an intense radiation of heat energy from a closely positioned-solid surface to penetrate the body of the coating to expand and soften the plastic compound and vaporize the solvent component, while exposing the exterior of the coating to a cooled solvent-vapor-condensing and moving atmosphere which is caused to move in the space between the coating and the said heat radiating solid surface and to operate recurrently first with a negative and then with a positive pressure relative to the film on the rigid surface.

2. The process of producing caps for bottles and the like from mobile plastic masses having fluent components, which comprises dropping a mass of predetermined quantity as a unit body onto the central portion of a rotating cap-mold, sealing the mold and spinning the mass to extend the same as a unit coating along the sides and onto the edge of the mold, confining air under compression within the mold cavity to compress the coating and expel the fluent component, and evacuating the mold cavity to expand the coating and expedite the removal in-vapor form of the fluent component expelled during the compres-' sion period and thereafter.

.3. The process of producing a hollow article from an organic plastic material which is main tained in a fluent condition by heat and pressure,

comprising delivering a mold charge of predetermined weight of the plastic material into a mold which is being rotated, heating the mold and changing the plane of its ax s of rotation so as quickly to spread the plastic material into a coating having the shape of the hollow article and the required thickne s of wall at diflerent points of the article, introducing a. superheated gaseous medium into the mold cavity under pressure when the mold charge is being spread, and when spread cooling said medium to rigidify the plastic coattain the fluency of the material, and thereafter medium, and subjecting the film and said medium in contact therewith to a plurality of fluctuations of pressure.

'l. The method of drying a film containing a volatile liquid, comprising exposing a surface of the film to a drying'rnedium, applying to the film radiant heat, and subjecting said medium and the film to a plurality of fluctuations of pressure.

8. The method of drying a film containing a volatile liquid, comprising exposing a surface of the film to a drying medium, applying radiant heat to the film through said surface, subjecting the film and said medium in contact therewith to a plurality of fluctuations of pressure, and moving said medium across the said surface.

9. The process of making and drying a film containing a volatile liquid and film-forming cellulose compounds, comprising spreading said compounds and said volatile liquid into a film by rotating a body thereof on a supporting surface, exposing the unsupported surface of the film to said drying medium, producing a plurality of fluctuations in the pressure of said medium during the drying operation, and moving said medium during .the drying operation over the film from the circumference towards the axis of the film.

10. The process of making and drying a film of material comprising a volatile liquid and filmforming cellulose compounds, which comprises placing a predetermined amount of said material on a revolving surface, imparting rotation from said surface to said material and thereby spreading the material into film form, subjecting the unsupported side of the spread film to a drying medium, moving said medium from the circumference of the film towards and along the axis of the film away from the surface of the film during drying, and producing a plurality of fluctuations in the pressure of said medium and on said film during the drying operation.

11. The method of drying a film consisting substantially of cellulose derivatives dispersed by and in solution with volatile substances, which comprises contacting a surface of the film with a drying medium, producing a plurality of fluctuations of pressure upon the medium and the film, moving fresh drying medium into contact with the film and saturated drying medium away from the film, and dehydrating said medium before it comes in contact with said surface of the film.

12. The method of drying a film body, consisting substantially of one or more cellulose derivatives, plasticizers, and volatile liquids having varying boiling points, which comprises subjecting a surface of the film to a drying medium, producing a pluralityof fluctuations in pressure on the medium and the film, and gradually increasing the successive pressures as the more volatile material is removed.

13. The method of drying a film, containing volatile material which comprises heating the film by radiant heat from a surface spaced from a surface of the film, passing adrying medium between said heating surface and said surface of the film, and subjecting said medium to fluctuations in pressure.

14. The method of drying a film containing volatile material, which comprises bringing a surface of the film in contact with a drying medium and heating the film by radiant heat passed through said medium and into the film.

15. The process of making and drying a film containing volatile liquid and a film forming material, which comprises spreading a predetermined quantity of said material by centrifugal force applied by a supporting surface in contact with one side of the film so formed, subjecting the other side of the film to a drying medium, and passing radiant heat through the drying medium and into the film and thereby heating the film during the drying operation.

16. The process of making an article from film forming material, which comprises spreading, a film into the form of the desired article on a supporting surface, drying the film on said surface,

mechanically raising a central portion of the film from the supporting surface, supplying air to the space beneath said raised portion, and removing the dried article by sub-atmospheric pressure on 'the side opposite from the supported surface.

17. The process of producing an article from film forming material, which comprises placing upon a surface of suitable shape a predetermined amount of material comprising volatile liquid and film forming cellulose materials which remain as a solid upon removal of the volatile liquid, rotating the surface and thereby spreading said predetermined amount of material into film form of the desired shape, during said rotation exposing the unsupported side of the film to a drying medium, and passing radiant heat through said drying medium into the film and thereby heating the film. 18. The process ofproducing a hollow artic from a definite quantity of thermo-setting plastic material, which comprises extruding a measured quantity of the plastic material from a supply thereof as a unit body in a molten state and delivering said body into the cavity of a mold, spreading said body during a predetermined period as a unitary'coating over the walls of said cavity, and then setting the said coating into a rigid state to produce the article therefrom by the application of additional heat to the coating and by simultaneously acting thereon with a compacting pressure communicated by a gaseous vehicle under super-atmospheric pressure.

19. The process of producing a hollow film wall article of soft collapsible structure from a fluent plastic material, which comprises delivering a measured quantity of the plastic material as a unit body into the bottom section of the cavity of a mold, spreading said body by centrifugal action as a unitary coating over the walls of said cavity, drying the said coating to make it solid, and removing it from the mold cavity by simultaneously applying an elevating force to the edge portion of the article to lift it from the mold cavity and pneumatic pressure between the walls of the mold cavity and the exterior face of the film to disengage the film from said walls.

20. The process of producing a hollow article from a thermo-plastic material which comprises delivering a definite quantity of the plastic material from a supply nozzle as a unit body directly to the bottom of a mold cavity, spreading all of the said body as a unitary coating on the walls of the mold cavity, applying heat to retain fluency in the plastic compound during the spreading period, then cooling the mold walls and introducing a cooling flow of air inside the mold cavity to rigidity the coating, following said operations lifting the rigidifled coating by its edge portion to a point removed from the mold cavity by means of an auxiliary mold part, and thereafter severing the coating from said auxiliary mold part to produce the article.

ENOCH T. FERNGREN. 

